Liquid-conductor heater device



Sept. 4,:1928.

M. W. HANKS ET AL LIQUID CONDUCTOR HEATER DEVICE Filed Oct. 1, 1923 2 Sheets-Sheet 1 INVENTORS Marsha/l W. Hanks,

Max Mason.

I BY

- 'ATToRNEY Sept. 4, 1928. 1,683,069

M. W. HANKS ET AL LIQUID CONDUCTOR HEATER DEVICE Filed 001:. 1, 1925 2 Sheets-Shet 2 F i g. 4.

& Q

.33 as ea Max Mason.

Patented Sept. 4, 1928.

' UNITED STATES PATENT OFFICE.

MARSHALL W. HANKS AND MAX. MASON, OF MADISON, WISCONSIN, ASSIGNORS T HANKSCRAFT COMPANY, A. CORPORATION OF WISCONSIN. 3

LIQUID-CONDUCTOR HEATER DEVICE.

Application filed October 1, 1923. serial a... 665,761.

' Our invention relates to liquid-conductor heating devices and it has particular relation to electrodes embodicdtherein.

Heretofore, liquid-conductor heating de-= vices have been designed and successfully o erated, by employingchemically treated trodes and utilizing e ectrodes or by employing untreated elecwater having suitable electrical conductivlty, either initially or by reason-of suitable treatment. In some instances, devices of the character above ind.icated have becomeinoperative or unreliable because-of impairment of the electrodes through loss of the chemical substances which they originally possessed or because of unsuitability of the liquid conductor.

This invention provides means for ensuring reliable operation and long life for liquidconductor heating devices without chemical treatmentof the electrodes or of the water through which. the current flows.

Electric current, passing through a liquid in sutlicient amount to vaporize it, materially alters its conductivity; because the vapor forms in bubbles which may permeate-the whole or a part of the liqiud carrying the current and thus tend to force it away from the, electrodes and to transform the original homogeneous body into a cellular structure offar less conductivity per unit volume, thus causing a decrease of current at constant avoiding or counteracting the above-mentioned conditlon, a marked decrease in current results, or, If a voltage suflicient to maintain a current of a desired amount is applied to ensure satisfactory vaporization, an undesirably high current will flow during the early part of the operation. Further-. more, if there isa gradual decrease in cur rent, as the liquid boils away, it will not shut oggsharply to zero, as is desirable in cases ere the apparatus is sodesigned as to automatically cut oif the heating effect upon boilin away of the liquid.

One of t e objects ofour invention is to provide a liquid-conductor heating device adapted for the utilization of non-treated electrodes and ordinary tap water;

Another object of our inventionis to ro- 'vide a liquid-conductor heating device avthercthrongh.-

ing a substantially constant and relatively low resistance, thereby producing proper vaporization. v

A furtl1er 'object of our invention is to provide a llquld-conductor heating device aving electrodes of such construction, as to ermit thee-scape of bubbles that are formed 1n the liquid w en heated by current flowing A still further object of our invention is to provide a liquid-conductor heating device having a plurality of electrodes and a liquid therebetween for the purpose of regulating the duration of current flow and for heating, through vaporization of the liquid between the electrodes, the electrodes being adapted to permit the escape of bubbles formed in the liquid when heated by the current flowing therethrough, being designedin such manner that the active area of the electrodes in contact with the conducting liquid is increased when bubbles are formed by the passage of current,

In the accompanying drawings:-

Figure 1 is a vertical, sectional View of a milk Warmer embodying our invention;

F1g.- 2 is a top plan view of the device shown in Fig. 1, the milk bottle being removcd,'an l a portion of the upper electrode" Fig. 6 is also a top plan view of another I pair of-clectrodes embodying another modified structure.

Fig. 7 is a vertical sectional View of an electrode embodying a still further modified structure' Fig. 8 is a top plan embodying another modified structure.

i J view of an electrode Fig. 9 is a plan view ofanelcctrode embodylng a further modification, and

Fig. 10fis a sectional view of the bottom portion of vessel and its electrodes, one of which islike that shown inFig. 9.

Tn Figs. 1 and 2 of the drawings, we have heating various quantities of milk.

As indicated in Figs. 1 and 2 of the draw ings, the measuring device 5 has a bottom opening which, before insertion of the device in the chamber 4, isclosed by a gravity-op erated valve, shown in Fig. 1 as a ball.

When the device is seated in the chamber 4, the bottom wall of the latter will unseat the valve and thus permit the liquid to flow from. the device into the main chamber.

The chamber 2 is provided with a pair of spaced-apart electrodes 6 and 7 in the bottom thereof, and is adapted to contain a vaporizable body of liquid 8 for the purpose of makingcircuit-closing contact with the electrodes 6 and 7.. The electrode 6 is of the disk type and is disposed in a depression 9 in the porcelain receptacle 1 and may be provided with a current-conducting screw 11 to serve as a terminal for anielectric conductor 12. Located in the center of the depression 9 is another depression 13 that is centered with an opening 14 in, which the screw 11 is located. A suitable packing material 15 may be placed in the depression 13 under the head of the screw 11 for the purpose of providing a liquid-tight seal. The electrode 6 may also be provided with a plurality of openings 16 to receive raised portions 17 that are located in the depression 9. The raised portions 17 of porcelain are provided for insulating the electrode 6 from a plurality of. current-carrying terminals 18. The termlnals 18 are connected to a ring 19 that is, in turn, connected to an electric conductor 21 for the purpose of transmitting electric current to the electrode 7. The electrode 7 is of disk type and'has one or more 0 enings 22 therein for the purpose of permittin bubbles to escape when the'liquid is heate by electric current flowing through it. The'openings in the electrode 7, when 'a plurality are provided, are spaced in such manner as to provide an unbroken ring 23' forfthe purpose of insuring positive contact with' the terminals 18. The

electrode 7 may be held in operative position by gravity or otherwise, if desired and, prefera ly, its-edge is provided with anon-conducting-coating 24, shown in enlarged detail in Fig. 3, for preventing a short circuit in case it accidentally engages the electrode 6 in v 'the operationof insertion or removal. The

coatin 24 may extend over any desired por: tion 0 the upper electrode, or, the protective dropped through a perforation and coming in-contact with the lower electrode would not come in contact with the upper electrode and thus cause a short circuit.

A circular plate 25 may be mounted on the under side of the receptacle for the purpose of enclosing the terminals thereof and may be held in position by an insulating nut 26 that cooperates with the extended portion of the screw 11. I

Referring to Fig. 4, a modification of our invention is illustrated in which a receptacle 27, having a body of vaporizable liquid 28 disposed therein, serves as one of the electrodes of the apparatus and is provided with a terminal connection 29. The receptacle 27' may have a cover member 31 and an inner electrode 32, also of dish-shape construction, disposed therein. The electrode 32 may have an opening or a plurality of openings 33 in the receptacle 27 by a non-conducting bushing 36. The outer face of the electrode 32 may be provided with a plurality of non-conducting spacers 37 for the purpose of insulating the electrode 32 from the receptacle electrode 27.

- A modified electrode structure, as shown in Fig. 5, comprises two interlaced spiral electrodes 38 and 39, respectively. The

electrodes 38 and 39 may be held in spaced" relation by suitable insulating members 41, The spiral passages 42 between the electrodes 38 and 39 permit bubbles to escape therethrough.

Another modified electrode structure, a

shown in Fig. 6, comprises two grid-type 1 posts (not shown).

The electrode 49, as shown in Fig, 8, is constructed of wire mesh 51 and, preferably,

is provided with a non-conducting rim 52.

Bubbles are permitted to escape through the openings 53.

In the modification shown in Figs. 9 and 10, the receptacle 1 and the lower electrode 6 are, or may be, like the corresponding parts previously shown and described but the upper electrode 54.- is provided with a lug. or car that makes contact with the head of a terminal bolt 56. The electrode is provided with insulating buttons 57 to rest upon the lower electrode. All or portions of the electrode edge may be provided with insulation, as indicated at 58, and the upper surface may be entirely coated, if desired.

In practisin our invention, we provide a ready release or vapor in order to minimize the average vapor content of the bubble structure, or we utilize the expansion of volume of the bubble-structure to bring into activity sufficient additional areas of electrodes so that the resulting total conductivity is not undesirably decreased by the bubble formation.

Area in excess of that which would be necessary to carry'a current through liquid alone is given to the electrodes, they beingin such positions that the desired operation is ensured by a small amount of liquid.

The various electrodes shown and described are only a few of many electrode structures that may be employed and, consequently, it is to be understood that the s ecific disclosures are not to be regarded as hmitin our invention to specific forms, dunensions or relative location of the essent1al elements, except insofar as hmltations are necessary to ensure satisfactory operation and desired results, in view of which only such limitations may properly be imposed as are set forth in the appended claims. i

The apparatus disclosed in the present application, including the perforated electrode or other means for effecting a rapid dissipation of energy, is claimed broadly in our co-pending application Serial No. 1,7 84, filed January 12, 1925. v

We claim as our invention:

1. An electric heating or cookin apparatus comprising a receptacle for a lmdy of vaporizab e liquid and two superposed and spaced-apart electrodes adapted for normal clrcuit-closing contact with said liquid, the upper electrode being held in position by gravity only and having a non-conducting rim.

2. An electric heating or. cooking :apparatus comprising a vessel adapted to contain a body of vaporizable liquid and a pair of superposed perforated electrodes in the bottom part of said vessel, the upper electrode being held in position by gravity only. 3. An electric heating or'cooking apparatus comprising. a receptacle adapted to contain a body of vapori zable liquid and a pairof superposed, spaced-apart electrodes in the bottom of said receptacle, the upper electrode being perforated and having a nonconducting rim and being held in operative position by gravity only.

4. An electric heating apparatus comprising a receptacle for vaporizable liquid having a main chamber containing a pair of superposed and spaced-apart electrodes, the .zpper electrode having one or more perforations, and an auxiliary chamber in open communication with said main chamber to receive a liquid-measuring device which auto matically discharges its contents into the main chamber when placed in the auxiliary chamber. 4 Y

5; An electric heating or cooking apparatus comprising a receptacle for a body of vaporizable liquid and a pair. of spacedapart electrodes in the bottom of said receptacle, at least one of said electrodes being constructed to permit the escape of bubbles, a plurality of current-conducting supports adapted for engagement with the upper electrode, said electrode being held in operative position by gravity only and having at least a portion of its outer peripheral surface coated with a non-conducting material to prevent a short circuit upon accidental engagement with the lower electrode.

6. An electric heating or cooking appa-' ratus comprising arec'eptacle for a body of vaporizable liquid and a plurality of spacedapart electrodes for making normal circuitclosing contact with said liquid, said electrodes being constructed to permit the escape of bubbles, and measuring means co-operating with said receptacle to determine the amount of liquid required for operation thereof.

7. An electric heating ratus comprising a liquid-containing vessel constituting an electrode and a perforated electrode supported in said vessel in spaced relation to the bottom thereof-and held in position by gravity. e

In testimony whereof, we have hereunto subscribed our names this 17th day of Sepor cooking appa' 

